Hours after the deadly rampage, the roommate called a tip line and told a detective he thought Roberts might be responsible.

The roommate said he once found a box of AR-15 ammunition at the house.

He told the detective Roberts had acted "weird" recently and talked about moving to Hawaii and selling his belongings on Craigslist. Roberts, in fact, had sold some things there, said the roommate.

The documents also showed the weapon used in last Tuesday's shooting, a Stag Arms brand AR-15 style rifle, was legally purchased by a friend of Roberts.

The night before the shooting, Roberts spent time with that friend, telling him he needed to get out town and needed a gun. When the friend awoke the next day, his rifle and Roberts were missing, he told a detective.